Air heating and conditioning



Jan. 20, 1942. E. J. TJERNLUND 2,270,395

AIR HEATING AND CONDITIONING APPARATUS Filed Jan. 2, 1940 3 SheetsSheet1 Cw r%% Jan. 20, 1942.

E. J. TJERNLUND AIR HEATING AND CONDITIONING APPARATUS Filed Jan. 2 19403 Sheets-Sheet 3 331 r/iyy/ Patented Jan. 20, 1942 UNITED STATES PATENTOFFICE AIR HEATING AND CONDITIONING APPARATUS Emil J. Tjernlund, St.Paul, Minn. Application January 2, 1940, Serial No. 311,979

Claims.

This invention relates to improvements in air heating and conditioningapparatus.

The primary object of the invention is to provide a simple, efilcient,compact and inexpensive unit heater and air conditioner which may beemployed for filtering, heating, and humidifying the air. Another objectis to provide an apparatus of this kind in which the maximum heatingeffect of the fuel may be utilized by the employment of a novel form ofcombustion chamber for feeding the heated gases into a series of downdraft fiues and thence into the smoke pipe, and a fan arranged to blowthe air over the entire exterior of this structure before finallydischarging the air into the heated and conditioned enclosure. A furtherobject is to provide an apparatus of this kind which is so arranged thatall heated parts are constantly wiped by the circulating air in processof heating and conditioning and in which the maximum volume of air, andwipage thereof, is secured at the point subjected to the greatest heat,thus making it possible to employ relatively light material in theconstruction of the apparatus without danger of burning out partsthereof and effecting a reduction in cost, size and weight of thecompleted assembly. A further object is to provide a novel arrangementof the air filtering and humidifying means by means of which all of thecirculated and recirculated air may be thoroughly filtered as it entersthe unit and then humidified to the proper degree as it leaves the unitand is conducted to the conditioned enclosure.

These and other more detailed and specific objects will be disclosed inthe course of the following specification, reference being had to theaccompanying drawings, in which- Fig. 1 is a vertical and longitudinalsection through my improved apparatus.

Fig. 2 is a plan view of the apparatus, the cover portion of theexterior casing being removed to disclose interior parts.

Fig. 3 is a horizontal section along the line 3-3 in Fig. 1, this viewalso showing a water heating coil in place.

Fig. 4 is a side elevation of the essential working elements of myinvention, with the exterior housing removed.

Fig. 5 is a fragmentary horizontal section along the line 5-5 in 4,showing only the fiue and smoke pipe assembly.

Referring now with more particularity and by reference numerals to thedrawings, A designates an exterior casing in which is mounted thefurnace housing or assembly B, the burner C, and

the fan D, these being the major parts of the structure.

The casing A comprises a closed bottom 6 supported above the floor levelby legs I, and the rectangular box-like shell made up of the sides 8-9and front and rear ends Ill-H. A cover I2 is secured atop the casing,but has the large inlet and outlet openings l3 and I4 to which thedischarge and return air ducts E and F are connected in usual manner.The frontal end In is removable for interior servicing and inspection ofparts, and fasteners iii are provided for looking this end in place. I

The furnace housing B comprises an upright rectangular portion l6defining and including a main chamber ll, but the frontal lower cornerof this portion I6 is extended forwardly in the form of a tapered inletportion 18 which terminates in a tubular neck l9 receiving the nozzle ofthe burner C as shown. The burner thus may discharge its heated productsinto the lower portion of the housing causing the heat and gases toascend therein.

The furnace housing also includes a series of vertically extended andtransversely spaced fiat flues 20 which are supported at the upperfrontal portion of the housing portion It by welding or otherwisefastening at 25. These flues are of rectangular cross section and openindividually, laterally, and rearwardly at their upper ends at 22 intothe upper frontal portion of the chamber. The rear upper wall of thehousing is curved upwardly and forwardly, as indicated at 23, so thatthe ascending gases in the chamber will be directed into the fiues andin which these gases will be reversed in their direction of travel toflow downwardly. At the lower ends of the flues 20 a smoke pipe 24 istransversely extended and supported by welding at 25 to the flues, andthe fiues each open by individual vents 26 .into this pipe. The ends ofthe smoke pipe extend to points adjacent the casing sides 8-9 which areprovided each with an opening 21 so that the usual chimney pipe G may beinserted into either end of the smoke pipe to carry off the gases. Theunused opening 21 may be closed by the removable cap plate 28, and itwill be evident that this arrangement makes it possible to locate theunit with either side adjacent the chimney and thus makes it possible tomeet the exigencies of any installation. v

The heatedgases thus circulating upwardly through the chamber I6,downwardly through the flues 20, and outwardly through the smoke pipe24, thus heat all surfaces of the furnace housing and the constructionis obviously such that a large heated area is provided in a small space.

It will be noted that the furnace housing B is supported in spacedrelation to all parts of the casing 0, thus affording air circulationspace around the bottom and all sides of the housing, as indicated at H.This construction further simplifies installation in that the unit maybe installed upon a wood floor without danger from a heated casingbottom, and rusting is prevented by free circulation of air beneath thebottom.

Legs 23 support the rear of the furnace housing B upon a transversemounting bar 30, and the frontal end is supported by an angularly formedmetal plate 3| which forms a wall isolating a lower frontal portion I ofthe interior of the casing A in which the burner C is mounted. The airfor combustion may be admitted into this space I through inlets 32 ineither front or lower portions of the casing, and this wall thusprevents gases of the burner from entering the circulating air streamthrough the unit. The lower rear margin 33 of the plate 3| rests on thebottom 6 and has an opening 34 nicely fitting the neck I! while thefrontal upper edge 35 of the plate is afllxed to and supported by anarrow cross strip 36.

The fan D is of the silent rotary type including a series of blades 31set in end rings 38 and supported on an axle 39 which in turn issupported and iournaled at its ends in bearings 40 on the fan housing4|. The fan is located eccentrically in said housing 4| and air is takenin through large circular end openings 42 concentric with the fan and isdischarged from the large rectangular discharge opening 43 in the rearside of the housing. The bearings 40 are supported upon end bars 44secured across the ends of the fan housing as shown. In mounting the fanD the lower surface 45 of the housing is rested upon themclined plate 3|above the burner C and the discharge opening 43 is thus disposedrearwardly to direct the discharge air blast downwardly around thetapered portion l8 of the furnace housing, as well as directly aroundthe smoke pipe 24 and upwardly between the dues 20. The housing tipsrearwardly, and at the upp r edge 46 of the discharge opening restsagainst the lower edge of a transverse partition plate 41 extendingbetween the casing sides 89 and depending from the cover l2 at a pointbetween the openings l3 and I4 therein. The arrangement is such that thefan itself is located substantially on a level with this margin 46, ofthe discharge opening 43, and the maximum flow of air will thus bedirected immediately around the smoke pipe 24 and between the fines.

Laterally arranged guide members or wings 48 and 49 are provided at eachside of the fan housing and at their rear edges fit tightly against thelateral margins of the discharge opening 43 and the rear end portion ofthe plate 3!, as indicated at 50, while their side portions flarerearwardly as at 51 to direct the air streams from the fan around thesides and bottom of the furnace housing 3.

The fan is rotated by a fan motor 52 supported upon the fan housing 4|by a plate 52a hung at one edge on the portion 41 (and so that the.

weight of the motor will aid in holding the fan in place), and thismotor is connected by a belt 53, trained over its drive pulley 54, to alarge pulley 55 on one end of the fan axle. Also located adjacent thismotor is a conventional thermostat J having its heat responsive elementK extended rearwardly through the partition 41 between the ilues 20 andwhich serves to control the operation of the unit in the usual manner.

An inner or secondary wall assembly, including upright sides 36 and 61and rear end 63, is provided and is supported within the casing A aroundthe furnace housing B in spaced relation between these parts in suchmanner as to form an insulating air space 53 around the heated parts ofthe casing. This structure prevents overheating and reduces waste heatradiation from the unit.

In operation the fan D serves to draw in air from the conditionedenclosure through the inlet l3 and discharges this air in a continuousstream around the furnace housing B so that it reenters the enclosure,in a heated condition, through the outlet l4. The construction andarrangement of the fan and furnace housing is such that the air willwipe all heated areas, including the bottom, of the housing and whichfeature not only provides a maximum of heating efllciency but alsoallows the use of an inexpensive and compact fabricated sheet metalassembly for the housing without danger of burning out. In thisconnection attention is directed to the flue assembly, and it will benoted that the spaces 60 between adjacent flues increase in widthoutwardly from.

the center (transversely) so that th amount of air will be evenlydistributed over all flues even though the maximum volume and velocityof airfiowage occurs at the center of the assembly.

The air entering the unit from the enclosure is caused to pass throughfilter elements 6| and 62 which are marginally supported in guides 63,secured to the side walls 89, in such manner that all communicationbetween the inlet l3 and the fan D must be through the conventionalfiltering material used in these members. The removable frontal end l0permits convenient servicing of all working parts of the unit, includingthese filters.

The air after filtering and heating is humidified by use of an elongatedwater pan or receptacle 64 which has a rounded bottom 65 to rest at theupper frontal portion of the furnacehousing B upon its rounded top 23.Hooks 66 depend from the pan and fit downwardly between the fiues 20 tohold the pan in place, and it will be noted that both front and rearwalls 61 and 68 of the pan are so inclined that the air ascendingvertically between flues and over the end 23 will now along in contactwith these walls to heat the water and facilitate humidification of theair. The pan may be arranged with an exterior feed and overflow systemin a usual manner.

The rate of air flow may be varied and controlled by a narrow damper orshutter 69 located at a lower rear portion of the fan housing 4| andprovided with an exterior handle I0 by which it may be oscillated tovarious positions relative to the direction of travel of the dischargedair. This damper may, of course, be automatically controlled if desired.

A by-pass duct or tubing ll connects the smoke pipe 24 horizontally withthe furnace chamber i1 and the usual water heating coil 12 may bearranged through this duct and in the chamber with the ends 13 extendedendwise from the smoke pipe and through the cap plate 28 for connectionto the water system. The rear of the furnace housing has a collarportion 14 normally closed by a removable door 15 and which facilitatesinstallation of the water coil serves as a cleanout.

The unit may of course be made up,..in any size desired, and lendsitself well to the modern practice of .omamental casing'lor such heatinginstallations. Further details as to the operation and utility of theassembly will be obvious to those skilled in the art, and it isunderstood that suitable modifications maybe made in the structure asdisclosed, provided such modifications come within the-spirit a d scopeof the appended claims.

Having now therefore fully ustrated and described my invention, what Iclaim to be new and desire to protect by Letters Patent is:

l. A heater comprising a burner, a chamber for carrying heated gasesupwardly from the burner, a smoke pipe located below the upper end ofsaid chamber and above the burner, a series 01 flues connecting theupper end of said chamber with the said smoke pipe, and a by-pass ductconnecting the smoke pipe directly with a lower portion of the saidchamber above the burner. I

2. A heatercomprising a furnace housing having a chamber, a burner fordischarging heated products of combustion into a lower portion of thechamber, a smoke pipe extended transversely above the burner and openingat one end for conducting gases therethrough, and a series of spaced,vertically extended flat flue members connecting the smoke pipe with anupper portion of the chamber. 4

3. A heater comprising a casing having side walls, a closed bottom and amedial dividing partition spaced from the said bottom, a furnace housingmounted in the casing at one side of the partition and spaced at allsides from said partition, side walls and bottom of the casing, the saidhousing including a tapering portion extending beneath said partition, aburner for projecting heated products into this tapered end of thehousing, a protective wall isolating the burner and its connection tothe furnace housing from the interior of the casing, and a fan supportedagainst the wall and partition for blowing air downwardly around saidtapered end and upwardly around all exterior surfaces of the furnacehousing and discharging the heated air from the casing.

4. A heater comprising a casing having side walls, a closed bottom and amedial dividing partition spaced from the said bottom, a furnace housingmounted in the casing at one side of the partition and spaced at allsides from said partition, side walls and bottom of the casing, the saidhousing including a tapering portion extending beneath said partition, aburner for and ' projecting heated products into this tapered portion ofthe housing, a wall member inclined tolower end of the partition toisolate a lower portion of the casing containing the burner and itsconnection to the furnace housing, and a fan ,one side of the partitionand having a tapering,

portion projecting beneath the partition, a burner for feeding heatedproducts into said tapered portion of the housing, a wallmembersupported 5! over the burner and beneath the partition, 9. fan

mounted on the said well member for blowing air downwardly beneath thepartition and around the said tapered portion of the furnace housing andaround all exterior surfaces of the housing, and side members mountedbetween the partition and wall ember at the outlet of the fan andflaring outwardly and away from the fan to direct the air dischargearound the said opening.

6. A heater comprising a furnace housing having a series of transverselyspaced and vertically extended flues, a smoke pipe connected to theflues, a burner associated with the housing, a fan supported with itsdischarge means in position to blow air between the flues, and the saidflues being so arranged that the spaces therebetween increase in sizetoward outer sides of the housing and the extremities of the fandischarge to thereby evenly distribute and appor-' tion the air from thefan in the spaces between the flues.

7. A furnace, comprising an outer casing, an upright inner furnacehousing supported in spaced relation on all sides with respect to thecasing, heating means in the lower end portion of the housing, a seriesof spaced flat flues communicating with one upper side of the housingand extending downwardly therefrom toward the heating means, theopposite upper side of the housing being curved to direct heatedproducts into the upper ends of the flues for travel downwardly therein,a smoke pipe disposed across the lower ends of the flues over theheating means and connected to said flues for carrying off heated 40products therefrom, and means for blowing air downwardly beneath thelower end of the housing, upwardly around all sides thereof, around thesmoke pipe and upwardly between the flues.

8. A furnace comprising an outer casing, an

upright inner furnace housing supported in spaced relation from top,bottom, and all sides of the casing and having a reduced extension at alower end, means for injecting heated products through'said extensionfor travel upwardly in the housing, one upper side of the housing beingcurved to direct said heated products toward the opposite side, a seriesof spaced upright flues supported from said opposite side of the housingand communicating therewith to receive the heated products from theupper end of the housing and carry them in a downward direction, a smokepipe disposed across lower ends of the flues above the extension of thehousing and connected to the flues for carrying oil the said 0 heatedproducts, and means for: blowing air ward said tapering portion andspaced from the downwardly around the extension, upwardly around allsides of the housing and around the smoke pipe upwardly between thefiues.

9. In a furnace, an upright housing, heating av a h s w h cl ned p t sap d as means in a lower portion of the housing, flues to rest upon thesaid wall and "having a discharge opening co-extensive with the spacebetween the wall and partition for discharging air over the exteriorsurfaces of the furnace housing, the

inclination of the wall member and fan directing the air from the fandownwardly-around the tapered portion of the housing.

5. A heater comprising a casing having side walls, a closed bottom and apartition spaced from said bottom, a furnace housing mounted at thesmoke pipe and the housing, and a water heating member extending fromwithin the said smoke pipe through the duct and into the housing abovethe lower portion thereof.

10. In a furnace, an upright housing, heating means in a lower portion0! the housing, tiues extending from an upper portion of the housingdownwardly alongside the housing to a point above the heating means, awater heating pipe extending through one end of the smoke pipe throughthe by-pass duct and into the housing above the lower end thereof, andthe said housing having an opening in the side opposite the bypass ductfor access to said water heating pipe.

EMIL J. TJERNLUND.

